Is continuous Erector Spinae Plane Block (ESPB) better than continuous Serratus Anterior Plane Block (SAPB) for mitral valve surgery via mini-thoracotomy? Results from a prospective observational study.

Aims: Chest wall blocks are effective alternatives for postoperative pain control in mitral valve surgery in right mini-thoracotomy (mini-MVS). We compared the efficacy of Serratus Anterior plane block (SAPB) and Erector Spinae plane block (ESPB) on postoperative pain relief after mini-MVS. Settings and Design: It is a prospective, observational study. Material and Methods: A total of 85 consecutive patients undergoing continuous SAPB and continuous ESPB for mini-MVS from March 2019 to October 2020 were included. The primary outcome was the assessment of postoperative pain evaluated as absolute value of NRS at 12, 24 and 48 h. Secondary outcomes were assessment of salvage analgesia (both opioids and NSAIDs), incidence of mild adverse effects (i.e. nausea, vomiting, and incorrect catheter placement) and timing of postoperative course (ICU and hospital length of stay, duration of mechanical ventilation, ventilator-free days). Results: The median NRS was 0.00 (0.00-3.00) at 12 h and 0.00 (0.00-2.00) at 24 and 48 h. No significant differences were observed between groups. Postoperative morphine consumption in the first 24 h was similar in both groups (P = 0.76), whereas between 24 and 48 h was significantly less in the ESPB group compared with SAPB group, P = 0.013. NSAIDs median consumption and Metoclopramide consumption were significantly lower in the ESPB group compared to SAPB group (P = 0.002 and P = 0.048, respectively). Conclusions: ESPB, even more than SAPB, appears to be a feasible and effective strategy for the management of postoperative pain, allowing good quality analgesia with low consumption of opioids, NSAIDs and antiemetic drugs.